Today, in our Linux Page (in Spanish) we have written few lines about a very particular icon Theme for KDE and Gnome (not till ready at the moment): Crystal Diamond. This icon Theme is really complete and the graphical effects are bright and very smooth. Moreover, the creator (an Italian geek) has developed different mods for the main Linux distribution (Ubuntu, Fedora, Suse, Mandriva RedHat, Debian, Gentoo etc..). We like this Theme also because it contains different icons for any application, so it is possible to 100% personalize our desktop and continuously change it tasting always new graphical solutions. 
